2-Component adhesive systems have generally been known for many years and are described in detail in the specialist literature. In such systems, an adhesive system consisting of two components is applied to the parts to be bonded, wherein two liquid components are conventionally used. For example, in the case of chemically reacting 2-component polymerization adhesive systems, one component comprises the monomer to be polymerized and an activator and the other component comprises a radical-forming substance (also called curing agent or initiator) and the monomer to be polymerized. After the two components have been mixed, or at least brought into contact, and activated, which in most cases takes place by means of heat, the radical-forming substance is cleaved into two radicals by the activator and the polymerization reaction of the monomers to be polymerized begins. The radical chain polymerization of the monomer then takes place until chain termination occurs, and the adhesive composition cures, whereby permanent bonding of the parts to be bonded is achieved.
A disadvantage of such liquid 2-component polymerization adhesive systems is that they are often not clean to use, because the two components must in most cases be applied in the liquid to pasty state to the parts to be bonded. This is a problem especially in the case of bonds over large areas and/or in applications in which the surfaces are uneven, for example sloping. In addition, activation of the adhesive system generally takes place at elevated temperatures, which can be a problem for sensitive substrates, such as, for example, anodized aluminum. A further disadvantage of such systems is that the storage stability of the two components can be critical. Moreover, after they have cured fully, conventional 2-component polymerization adhesive systems are frequently associated with problems which only come to light in the event of shocks. Thus, in the case of the systems of the prior art, cracks or breaks can occur in the region of the bonds as a result of violent shocks.
Accordingly, the object underlying the present invention is to provide an improved reactive 2-component adhesive system. Against this background, the present invention proposes a reactive 2-component adhesive system in film form for bonding various materials, in order to avoid the above-described problems of known, liquid 2-component adhesive systems.
In particular, there is provided a reactive 2-component adhesive system in film form which is simple to handle and ideally already exhibits tackiness, so that there is no slipping when applied to the substrates to be bonded and more precise bonding is possible than with the liquid 2-component polymerization adhesive systems known in the prior art.